Association of autism diagnosis and polygenic scores with eating disorder severity

Barriers and facilitators to ethical co-production with Autistic people with an eating disorder

BACKGROUND

Co-production is the collaboration between researchers and the lived experience community in designing, conducting and sharing research. The importance of co-production is increasingly advocated in both the autism and eating disorder fields. Despite this, there remains a lack of clarity at how to define, apply and conduct ethical co-production. Understanding common challenges and what we can do to overcome these challenges are integral to ensuring ethical and meaningful research with Autistic people with an eating disorder. The current study therefore explored: What are the barriers and facilitators to ethical co-production with Autistic people with an ED?

METHODS

Five workshops were conducted with 30 collaborators exploring barriers and facilitators to ethical co-production. Synchronous (online workshops) and asynchronous (offline discussion forum) data was analysed using thematic analysis. Themes were co-produced by a neurotypical and Autistic researcher with lived/living experience of an eating disorder.

RESULTS

Four themes were identified that explored barriers to ethical co-production: unequal partnerships, the inaccessibility of research, excluded by diagnoses and communication differences. Three themes were identified with regards to facilitators of ethical co-production: shared power (with sub-themes relationships, not roles and creative compensation), clarity and transparency and autism-affirming approaches.

DISCUSSION

Conducting ethical co-production with Autistic people with eating disorders has the potential to generate meaningful research that can be translated into improving the lives of the Autistic and eating disorder community. To achieve this, co-production teams should strive towards shared power and long-term relationships, adapting for communication differences and preferences and operating firmly within an autism-affirming framework. It is hoped that study findings will inspire collaboration, discussion and novel, translatable research.

Social communication and restricted, repetitive behavior as assessed with a diagnostic tool for autism (ADOS-2) in women with anorexia nervosa

OBJECTIVE

In anorexia nervosa (AN), the traits of autism spectrum disorder (ASD) are associated with poor outcomes. However, the subtle nature of these characteristics remains poorly understood. We investigated the in-depth patterns of ASD traits using Autism Diagnostic Observation Schedule-Second Edition (ADOS-2) in women with AN.

METHODS

Of 28 women with ICD-10 AN, 16 (age 19-30 years) participated in the ADOS-2, a video-recorded, semistructured diagnostic assessment for social communication and interaction and restricted, repetitive behaviors and interests related to ASD. None of the participants had previously been diagnosed with ASD. Other measurements included the Eating Disorder Examination Questionnaire and the Wechsler Abbreviated Scale of Intelligence-IV.

RESULTS

Five individuals (18% of all, 31% of those assessed) scored above the cutoff for autism in ADOS-2. They had challenges in social communication and interaction, manifesting as sustained difficulties in social relationships and deficits in conversation skills. Few described being frequently misunderstood by others, including in the eating disorder treatment settings. Three individuals showed prominent restricted and repetitive behaviors such as ritual seeking, eating-related routines, sensory sensitivity related to food texture and selective eating, and intense interest in specific topics. The mean duration of AN in women above the cutoff was twice as long compared with those below (12.3 vs. 6.2 years).

DISCUSSION

The ASD-related characteristics and behavior appear to contribute to the manifestation and duration of AN in a subgroup of women. Among these women, the traits of ASD appear to be mixed with eating disorder symptoms, which should be taken into account in the treatment.

Potential mechanisms underlying the association between feeding and eating disorders and autism

There is a reliable association between autism and Feeding and Eating Disorders. Concerningly, where these two conditions co-occur, clinical outcomes of Feeding and Eating Disorders are significantly worse, and treatment less effective, than when the Feeding and Eating Disorders occur in neurotypical individuals. Problematically, the reason for the association between autism and Feeding and Eating Disorders is poorly understood, which constrains advances in clinical care. This paper outlines several possible mechanisms that may underlie the observed association and suggests ways in which they may be empirically tested. Mechanisms are split into those producing an artefactual association, and those reflecting a genuine link between conditions. Artefactual associations may be due to conceptual overlap in both diagnostic criteria and measurement, Feeding and Eating Disorders causing transient autistic traits, or the association being non-specific in nature. A genuine association between autism and Feeding and Eating Disorders may be due to common causal factors, autism directly or indirectly causing Feeding and Eating Disorders, and Feeding and Eating Disorders being a female manifestation of autism.

Overlap of eating disorders and neurodivergence: the role of inhibitory control

BACKGROUND

Difficulties with inhibitory control have been identified in eating disorders (EDs) and neurodevelopmental disorders (NDs; including attention deficit hyperactivity disorder (ADHD) and autism spectrum disorder), and there appear to be parallels between the expression of these impairments. It is theorised that impairments in inhibitory control within NDs may represent a unique vulnerability for eating disorders (EDs), and this same mechanism may contribute to poorer treatment outcomes. This review seeks to determine the state of the literature concerning the role of inhibitory control in the overlap of EDs and neurodivergence.

METHOD

A scoping review was conducted to summarise extant research, and to identify gaps in the existing knowledge base. Scopus, Medline, PsycInfo, Embase, and ProQuest were systematically searched. Studies were included if the study measured traits of ADHD or autism, and symptoms of ED, and required participants to complete a performance task measure of inhibitory control. Where studies included a cohort with both an ND and ED, these results had to be reported separately from cohorts with a singular diagnosis. Studies were required to be published in English, within the last 10 years.

RESULTS

No studies explored the relationship between autism and EDs using behavioural measures of inhibitory control. Four studies exploring the relationship between ADHD and EDs using behavioural measures of inhibitory control met selection criteria. These studies showed a multifaceted relationship between these conditions, with differences emerging between domains of inhibitory control. ADHD symptoms predicted poorer performance on measures of response inhibition in a non-clinical sample; this was not replicated in clinical samples, nor was there a significant association with EDs. Both ADHD and ED symptoms are associated with poor performance on attentional control measures; where these diagnoses were combined, performance was worse than for those with a singular diagnosis of ADHD. This was not replicated when compared to those with only ED diagnoses.

CONCLUSION

Impairments in attentional control may represent a unique vulnerability for the development of an ED and contribute to poor treatment outcomes. Further research is needed to explore the role of inhibitory control in EDs, ADHD and autism, including the use of both self-report and behavioural measures to capture the domains of inhibitory control.

Inclusion of the severe and enduring anorexia nervosa phenotype in genetics research: a scoping review

BACKGROUND

Anorexia nervosa has one of the highest mortality rates of all mental illnesses. For those who survive, less than 70% fully recover, with many going on to develop a more severe and enduring phenotype. Research now suggests that genetics plays a role in the development and persistence of anorexia nervosa. Inclusion of participants with more severe and enduring illness in genetics studies of anorexia nervosa is critical.

OBJECTIVE

The primary goal of this review was to assess the inclusion of participants meeting the criteria for the severe enduring anorexia nervosa phenotype in genetics research by (1) identifying the most widely used defining criteria for severe enduring anorexia nervosa and (2) performing a review of the genetics literature to assess the inclusion of participants meeting the identified criteria.

METHODS

Searches of the genetics literature from 2012 to 2023 were performed in the PubMed, PsycINFO, and Web of Science databases. Publications were selected per the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR). The criteria used to define the severe and enduring anorexia nervosa phenotype were derived by how often they were used in the literature since 2017. The publications identified through the literature search were then assessed for inclusion of participants meeting these criteria.

RESULTS

most prevalent criteria used to define severe enduring anorexia nervosa in the literature were an illness duration of ≥ 7 years, lack of positive response to at least two previous evidence-based treatments, a body mass index meeting the Diagnostic and Statistical Manual of Mental Disorders-5 for extreme anorexia nervosa, and an assessment of psychological and/or behavioral severity indicating a significant impact on quality of life. There was a lack of consistent identification and inclusion of those meeting the criteria for severe enduring anorexia nervosa in the genetics literature.

DISCUSSION

This lack of consistent identification and inclusion of patients with severe enduring anorexia nervosa in genetics research has the potential to hamper the isolation of risk loci and the development of new, more effective treatment options for patients with anorexia nervosa.

A longitudinal study of autism spectrum disorder characteristics in adolescents with restrictive type anorexia nervosa during and after underweight

OBJECTIVES

This prospective, longitudinal study aims to compare the prevalence of autism spectrum disorder (ASD) characteristics in adolescents with anorexia nervosa (AN) during and after underweight in order to help unravel the complex link between both conditions.

METHODS

24 adolescents with AN completed the youth self-report, autism spectrum quotient (AQ) or autism spectrum quotient adolescent version (AQ - adolescent) and a questionnaire designed by the researchers during a state of underweight and after weight recovery.

RESULTS

AQ total score and several AQ subscale scores at the time of underweight are significantly higher than after weight recovery with medium to large effect sizes. Linear modelling cannot prove a significant effect of weight gain, internalizing problems or medication use on AQ score, but it does show an association between AQ during underweight and AQ after weight recovery.

CONCLUSIONS

The results highlight the complexity of the link between AN and ASD characteristics. Although a clear change in AQ score is seen in part of the participants, this effect cannot be generalized and a link with weight change cannot be demonstrated. It seems likely that ASD characteristics in AN are a combination of trait and state: underweight and starvation might exacerbate potentially present traits. Part of our results may indicate the existence of subgroups based on AQ score during underweight. Our study supports the theory that more ASD characteristics at T1 may result in a poorer outcome and a higher need for specified and intensive treatment.

Risk of suicide attempt with gender diversity and neurodiversity

There is growing concern about psychiatric illness co-occurring with gender-diversity and neurodiversity, including risk of suicidal behavior. We carried out systematic reviews of research literature pertaining to suicide attempt rates in association with gender- and neurodiversity, with meta-analysis of findings. Rates of suicidal acts ranked: gender-diverse versus controls (20.1% vs. 1.90%; highly significant) > autism spectrum disorder (4.51% vs. 1.00%; highly significant) > attention deficit-hyperactivity disorder (7.52% vs. 4.09%; not significant). Attempt rates also were greater among controls who included sexual minorities (5.35% vs. 1.41%). The rate among male-to-female transgender subjects (29.1%) was slightly lower than in female-to-male subjects (30.7%), who also were encountered 24.3% more often. In sum, suicidal risk was much greater with gender-diversity than neurodiversity. Suicide attempts rate was somewhat greater among female-to-male transgender subjects. Available information was insufficient to test whether suicidal risk would be even greater among persons with both gender- and neurodiversity.

The impact of genetic risk for schizophrenia on eating disorder clinical presentations

A growing body of literature recognizes associations between eating disorders (EDs) and schizophrenia and suggests that familial liability to schizophrenia in individuals with anorexia nervosa (AN) reveals distinct patterns of clinical outcomes. To further investigate the influence of schizophrenia genetic liability among individuals with EDs, we evaluated the associations between schizophrenia polygenic risk scores (PRS) and clinical presentations of individuals with EDs including their overall health condition and ED-related symptoms. Using data from two previous studies of the genetics of EDs comprising 3,573 Anorexia Nervosa Genetics Initiative (ANGI) cases and 696 Binge Eating Genetics Initiative (BEGIN) cases born after 1973 and linked to the Swedish National Patient Register, we examined the association of schizophrenia PRS on ED clinical features, psychiatric comorbidities, and somatic and mental health burden. Among ANGI cases, higher schizophrenia PRS was statistically significantly associated with higher risk of major depressive disorder (MDD) measured by hazard ratio (HR) with 95% confidence interval (CI) (HR [95% CI]: 1.07 [1.02, 1.13]) and substance abuse disorder (SUD) (HR [95% CI]: 1.14 [1.03, 1.25]) after applying multiple testing correction. Additionally, higher schizophrenia PRS was associated with decreased clinical impairment assessment scores (-0.56, 95% CI: [-1.04, -0.08]) at the conventional significance level (p < 0.05). Further, in BEGIN cases, higher schizophrenia PRS was statistically significantly associated with earlier age at first ED symptom (-0.35 year, 95% CI: [-0.64, -0.06]), higher ED symptom scores (0.16, 95% CI: [0.04, 0.29]), higher risk of MDD (HR [95% CI]: 1.18 [1.04, 1.34]) and SUD (HR [95% CI]: 1.36 [1.07, 1.73]). Similar, but attenuated, patterns held in the subgroup of exclusively AN vs other eating disorder (OED) cases. These results suggest a similar pattern of influence of schizophrenia PRS for AN and OED cases in terms of psychiatric comorbidities, but a different pattern in terms of ED-related clinical features. The disparity of the effect of schizophrenia PRS on AN vs OED merits further investigation.